CN1363991A - Multi-target non-linear anti-interference exciting control method and device for electric generator - Google Patents

Abstract

The invention relates to a method and device of magnetizing control for elctric generator with functions of multiple purposes, non-linear and anti interference. First, signals of phase voltage and phase current collected from the generator are sent to A/D converter for sampling. CPU reads out the sampled data stored on temporary storage of A/D converter and calculates out the amplitude of real and image parts in phase voltage and phase current of generator by using 16 points Fourier sampling algorithm. Then, Qg, Ug, UGd, Ugq, delta Ug, delta omega, delta are calculated out. Further the magnetizing control rule of multiple purposes, non-linear and anti interference is calculated. Last, The time for sending out pulse trigged by controlled silicon is determined so as to obtain the timer value of microprocessor, thus a working cycle for controlling non-linear dynamic excitation is completed. The method and device can increase stability of generators running in parallel, meanwhile can guarantee the accuracy of regulating voltage of generator so as to control dynamic and static multi performances of system effectively.

Description

Generator multi-target non-linear anti-interference exciting control method and device

Technical field

The present invention relates to a kind of multi-target non-linear anti-interference exciting control method of generator and be the hardware controller of software kernels, belong to motor automatic control technology field with this control method.

Background technology

The main effect of generator excitation control is: the regulator generator terminal voltage is moved at the set-point place; Load or burden without work between the generator of reasonable distribution parallel running; When system is disturbed, improve the stability of parallel running of generators.Continuous expansion along with electric power system networking scale, especially in the electric power system of long distance power transmission and contact weakness, when the circuit transmission power is big, tend to occur the instability problem of parallel running, traditional PID formula field regulator can not solve the problem of above-mentioned appearance soon.Studies show that in a large number, improving excitation control method is one of economic and effective major measure that improves power system operation stability, thereby had multiple improved excitation control method, as linear optimal excitation control (LOEC), non-linear exciter control (NEC) etc., wherein non-linear exciter is controlled to be and optimizes and advanced control method.But existing non-linear exciter control method all designs by the single goal method for designing, therefore often being prone to the dynamic and static performance of generator is difficult to satisfactory to both parties situation, promptly improve operation stability and guarantee that these two functions of pressure regulation precision are difficult to improve simultaneously, have in addition generator voltage occurs and change the situation that is offset given operating point with the mechanical output of its input.

Summary of the invention

Problem to be solved by this invention is multi-target non-linear anti-interference exciting control method and the device that has proposed a kind of generator at the deficiency of above-mentioned prior art existence, it is when obviously improving parallel running of generators stability, still can accurately guarantee the pressure regulation precision of generator voltage, thus dynamic and static performance polynary, control system effectively.

The present invention for the excitation control method technical scheme that problem adopted of the above-mentioned proposition of solution is: at first gather phase voltage u from generator _a, u _b, u _cWith phase current i _a, i _b, i _cSignal is sent into A/D converter and is sampled, and after sampling is finished, these data is read the phase voltage real part U that calculates generator among the CPU by 16 Fu Shi sampling algorithms from the buffer of A/D _GaR, U _GbR, U _GcRWith imaginary part U _GaI, U _GbI, U _GcIAmplitude, and phase current real part I _GaR, I _GbR, I _GcRWith imaginary part I _GaI, I _GbI, I _GcIAmplitude after the sampled data of all passages calculated, further calculates Q again _G, U _G, U _Gd, U _Gq, Δ U _G, Δ ω, And δ, calculate multi-target non-linear anti-interference excitation control law then, further calculate the pilot angle α of controllable silicon in the three-phase fully-controlled rectifier, determine sending the time of SCR trigger pulse signal at last again according to excitation control law result of calculation UE, provide the timing value Na of timing microprocessor device, promptly finish one-period the Nonlinear Dynamic excitation Control work of generator.

In the such scheme, generator phase voltage real part U _GaR, U _GbR, U _GcRComputing formula be: $U_{\mathrm{GxR}}=\frac{1}{8}[u_{x4}-u_{x12}+(u_{x1}+u_{x7}-u_{x9}-u_{x15})\sin \frac{\mathrm{\&pi;}}{8}$ $+(u_{x2}+u_{x6}-u_{x10}-u_{x14})\sin \frac{\mathrm{\&pi;}}{4}$ $+(u_{x3}+u_{x5}-u_{x11}-u_{x13})\sin \frac{3\mathrm{\&pi;}}{8}]$ Phase voltage imaginary part U _GaI, U _GbI, U _GcIComputing formula be: $U_{\mathrm{GxI}}=\frac{1}{8}[u_{x0}-u_{x8}+(u_{x1}-u_{x7}-u_{x9}+u_{x15})\cos \frac{\mathrm{\&pi;}}{8}$ $+(u_{x2}-u_{x6}-u_{x10}+i_{x14})\cos \frac{\mathrm{\&pi;}}{4}$ $+(u_{x3}-u_{x5}-u_{x11}+u_{x13})\mathrm{<figure-callout\; id="3"\; label="cos"\; filenames="A0211550400121.png"\; state="\{\{state\}\}">cos</figure-callout>}\frac{3\mathrm{\&pi;}}{8}]$ Phase current real part I _GaR, I _GbR, I _GcRComputing formula be: $I_{\mathrm{GXR}}=\frac{1}{8}[i_{x1}-i_{x12}+(i_{x1}+i_{x7}-i_{x9}-i_{x15})\sin \frac{\mathrm{\&pi;}}{8}$ $+(i_{x2}+i_{x6}-i_{x10}-i_{x14})\sin \frac{\mathrm{\&pi;}}{4}$ $+(i_{\mathrm{<figure-callout\; id="3"\; label="x"\; filenames="A0211550400121.png"\; state="\{\{state\}\}">x</figure-callout>}3}+i_{x5}-i_{x11}-i_{x13})\sin \frac{3\mathrm{\&pi;}}{8}]$ Phase current imaginary part I _GaI, I _GbI, I _GCIComputing formula be: $I_{\mathrm{GXI}}=\frac{1}{8}[i_{x0}-i_{x8}+(i_{x1}+i_{x7}-i_{x9}-i_{x15})\cos \frac{\mathrm{\&pi;}}{8}$ $+(i_{x2}-i_{x6}-i_{x10}+i_{x14})\cos \frac{\mathrm{\&pi;}}{4}$ $+(i_{x3}-i_{x5}-i_{x11}+i_{x13})\mathrm{<figure-callout\; id="3"\; label="cos"\; filenames="A0211550400121.png"\; state="\{\{state\}\}">cos</figure-callout>}\frac{3\mathrm{\&pi;}}{8}]$

Above-mentioned various middle x gets a, b, c, u respectively _X0～U _X15Be each phase voltage sampled value, i _X0～i _X15Be each phase current sampling value;

The formula of multi-target non-linear anti-interference excitation control law is: $U_E=(\frac{K_1{Q}_G}{U_G}+U_G)+(K_2\sin \mathrm{\&delta;}-K_3\frac{U_{\mathrm{Gd}}}{U_{\mathrm{Gq}}}\cos \mathrm{\&delta;})\mathrm{\&Delta;\&omega;}+K_4\frac{U_G}{U_{\mathrm{Gq}}}(-k_1\mathrm{\&Delta;}{U}_G-k_2\mathrm{\&Delta;\&omega;}-{\mathrm{<figure-callout\; id="3"\; label="k"\; filenames="A0211550400121.png"\; state="\{\{state\}\}">k</figure-callout>}}_3\mathrm{\&Delta;}\stackrel{\&CenterDot;}{\mathrm{\&omega;}})$

K in the formula ₁, K ₂, K ₃, K ₄, k ₁, k ₂, k ₃Be constant, can be in the real number scope value, common span is: K ₁=1.2～2.2, K ₂=0.56～33.25, K ₃=1.1～40.89, K ₄=2.06～42.75, k ₁, k ₂, k ₃Determine Q by the linear optimal computational methods _GBe generator three phase reactive power, U _GBe generator end phase voltage amplitude, U _GdBe generator end phase voltage direct axis component amplitude, U _GqBe generator end phase voltage quadrature axis component amplitude, δ is a generator's power and angle, and Δ ω is a generator amature angular speed deviation,

Be generator amature angular acceleration deviation.

Wherein the acquisition method of merit angle δ is seen Fig. 6: certain position on generator amature q axle (A point in as figure) boring, and rotation-speed measuring device is installed.At first measure bore position and generator floating voltage U _G0Phase difference θ ₀(can accurately beat on the q axle as if bore position, then θ ₀Approach 0), measure bore position and generator loading voltage U behind the question generator on-load _GPhase difference θ ₁, then the merit angle of generator can calculate δ=θ ₁-θ ₀Need cooperate the direction of output of a generator to detect when measuring the merit angle, to judge the direction at merit angle.

Control law is calculated as follows out silicon controlled pilot angle α in the three-phase fully-controlled rectifier after calculating and finishing:

α＝cos ^-1(Eqe/1.35U ₁)。

In the formula: U ₁For being added to the line voltage effective value of the alternating voltage on the full-controlled rectifier device.After pilot angle α calculates, just can determine sending the time of SCR trigger pulse signal, directly provide the timing value Na of timing microprocessor device in the following formula:

In the formula: T is a synchronous signal cycle, and fd is the timer frequency.

The technical scheme of excitation controlling device of the present invention is: be made up of data acquisition circuit, microcontroller circuit and control impuls output circuit, difference is to adopt high performance eight passages, four road synchronized sampling A/D converter U20 in data acquisition circuit, CPU adopts high performance digital signal processor (DSP) U1 and tape program memory in the microcontroller circuit, and the memory under program storage has the programming of multi-target non-linear anti-interference excitation control law.

The course of work of excitation controlling device of the present invention is: when generator operation, pass through data acquisition circuit, gather generator voltage, current signal, send into A/D converter, and will change data deposit in the memory, treat that digital signal processor (DSP) sends when reading signal, data are imported among the DSP handled, and calculate the required exciting voltage U of generator at that time according to the anti-excitation control law of multi-target non-linear calculating formula _E, along with the variation of generator operating condition, the required exciting voltage U that calculates _EAlso will change.That calculates according to this goes out pilot angle α and SCR trigger pulse (U _Ga1, U _Gc2, U _Gb3, U _Ga4, U _Gc5, U _Gb6) the time of sending N _aAlso change, thereby the DC excitation voltage of control three-phase fully-controlled rectifier output changes, and reaches regulator generator terminal voltage and the purpose of improving generator operation stability thereupon.

Good effect of the present invention is: the dynamic and static performance that 1, can support control generator excitation control system polynary, effectively, make that the dynamic and static performance of system is easier to hold, solved in the past that existing dynamic and static performance to system is difficult to hold the problem of attending to one thing and lose sight of another in the non-linear exciter control method.2. can be when obviously improving parallel running of generators stability, still can accurately guarantee the pressure regulation precision of generator voltage, can in whole stable operation zone, suppress the disturbance of unit mechanical output variation effectively to set end voltage, keep generator voltage exactly and move on set-point, the system of assurance has good static properties.3, can control generator and in running, have good dynamic property, can effectively suppress system oscillation, improve the stability of power system operation, obviously improve the stability power limit of transmission line, thereby fully excavate and utilize the conveying capacity of circuit.4, in this control method, have clear and definite adjusting pressure measure, make stable control and Regulation Control organically merge in a control law.And include clear and definite adjusting pressure measure in control law is not to be that each excitation controlling Design scheme can both be accomplished.5, in carrying out multiobject deterministic process, pay attention to making designed non-linear anti-interference exciting control method concisely practical, be easy to realize the multicomputer decentralized coordinating control of electric power system, be easy in industry, implement.6, the anti-excitation control method of multi-target non-linear is because irrelevant with Δ δ, thereby makes this control method become a real non-linear exciter control method that has nothing to do with design and operation point.

Description of drawings

Fig. 1 is the annexation schematic diagram of excitation controlling device of the present invention and generator.

Fig. 2 is the circuit block diagram of excitation controlling device of the present invention.

Fig. 3 is data acquisition circuit schematic diagram in the excitation controlling device of the present invention.

Fig. 4 is microcontroller circuit schematic diagram in the excitation controlling device of the present invention.

Fig. 5 is control impuls output circuit schematic diagram in the excitation controlling device of the present invention.

Fig. 6 is the acquisition method schematic diagram of merit of the present invention angle δ.

Fig. 7, Fig. 8 are respectively in the one embodiment of the invention multi-target non-linear anti-interference excitation control oscillogram and the control of PID excitation as a result oscillogram as a result.

Fig. 9, Figure 10 are respectively in the another embodiment of the present invention multi-target non-linear anti-interference excitation control oscillogram and the control of PID excitation as a result oscillogram as a result.

Embodiment

The embodiment of excitation controlling device of the present invention at first is described below in conjunction with accompanying drawing 1-5, mainly by data acquisition circuit, microcontroller circuit and control impuls output circuit, and the human-computer interaction device comprises display, keyboard is formed, as shown in Figure 2, data acquisition circuit as shown in Figure 3, comprise filter circuit and A/D converter, filter circuit is by R45-R60, C1-C16, Z1-Z16 totally eight covers forms, be used for the generator voltage that filtering is gathered, humorous wave of high order in the current signal and high frequency random disturbances signal, A/D converter is by U20 (MAX125) and C25-C29, C38, C39, R109 and A/D converter crystal oscillator X2 constitute, be 3 μ s single channel change-over time of U20, allow bipolarity ± 5V input, DCB directly joins with microprocessor, and the filtered signal of A/D converter reception prime is a digital signal with analog-signal transitions, send into then among the container U4 of microprocessor, in order to using, A/D converter can be realized four road synchronized samplings, can effectively improve the signal sampling precision; Microcontroller circuit includes digital signal processor (DSP) U1, electrification reset chip U2, E as shown in Figure 4 ²PORM memory U3, data memory U4, and crystal oscillator X1, pull out bit switch S1 at exclusion RP1, and U1 inside has the Flash type memory under program of 16K * 16bit, and selecting model for use is TMS320F240; The control impuls output circuit as shown in Figure 5, comprise: triode N1-N6, pulse transformer T1-T6, diode DM1-DM8, light-emitting diode L1-L6, resistance R M3-RM14, capacitor C 31-C36, form six road pulse signal amplification circuits, be respectively applied for six controllable silicons that trigger in an orderly manner in the three phase controlled rectifier circuit, to change its conducting state, reach the purpose that changes the generator excitation voltage size, wherein triode is used for the pulse amplification, and pulse transformer is used for amplifying and the transmission pulse signal, carries out electrical isolation simultaneously, when diode and resistance are used for the triode shutoff, release energy in the pulse transformer inductance coil, diode is used for preventing the anti-microprocessor of bringing into of instantaneous interference signal of three-phase fully-controlled rectifier, electric capacity can prevent that instantaneous interference from causing the pulse false triggering.When device of the present invention uses, as shown in Figure 1, the current transformer LH and the voltage transformer YH of the input of its prime data acquisition circuit and generator output end join, so that the signal that dynamic acquisition is required, thereafter the output of Ji control impuls output circuit and the silicon controlled control utmost point joins, controlling its trigger angle, thus the exciting voltage of regulating generator.LBY is an excitation transformer, and LBL is an exciter converter, is used to generator that the exciting power source is provided.

The embodiment of excitation control method of the present invention 7,8,9,10 further is described below in conjunction with the accompanying drawings:

Device of the present invention has been carried out real-time control experiment on generator an experiment, and the foundation of model is that to power to system by single time 220KV transmission line through transformer boosts after with a 125MW hydraulic generator unit be with reference to prototype in the experiment.Experimental model parameter such as following table:

Parameter name	Parameter value	Parameter name	Parameter value	Parameter name	Parameter value
						Generator capacity Se (KVA)	??3.47	Generator speed n (rpm)	??1500	D-axis transient state reactance Xd ' (pu)	??0.127
The generator Pe (KW) that gains merit	??3.038	Chronic time constant T; (s)	??7.71	D-axis subtranient reactance Xd " (pu)	??0.073
						Generator voltage Ufe (V)	??230	Transient state time constant Tdi (s)	??5.75	Intersection number synchronous reactance Xq (pu)	??0.165
Transformer voltage Ute (V)	??800	Direct-axis synchronous reactance Xd (pu)	??0.676	Hand over axle subtranient reactance Xq " (pu)	??0.08

Experimental program is chosen as follows:

[scheme 1]: system's initial launch point: meritorious 0.46 (pu), power factor 0.95 lags behind.Disturbance: input mechanical output disturbance Δ P _m=0.23 (pu).

[scheme 2]: system's initial launch point: meritorious 0.69 (pu), power factor 0.8 lags behind.Disturbance: three relative ground circuits, through t _rExcision after=0.36 second.

Interpretation:

In order to compare, each experimental program also carries out the excitation control method of PID formula simultaneously, experimental result see Fig. 7,8 and Fig. 9,10 figure in the arrangement from top to bottom of physical quantity curve be respectively: A phase current I _Ga, A phase voltage U _Ga, exciting voltage U _E, active power P _G

The experimental result of scheme 1 is seen Fig. 7,8.Fig. 7 is a multi-target non-linear anti-interference excitation control oscillogram as a result, and Fig. 8 controls oscillogram as a result for the PID excitation.Comparison diagram 7 and Fig. 8 can find out clearly that multi-target non-linear anti-interference exciting control method calms down the ability of vibration and obviously be better than the PID excitation control method.Under the effect of multi-target non-linear anti-interference excitation control law, the unit vibration that disturbance causes is only just calmed down behind a crest, and under the effect of PID excitation control law, vibration needs just gradually mild through 8-9 cycle.In addition, can see that also under the effect of multi-target non-linear anti-interference excitation control law, although generator active power has increased, set end voltage can not be offset.

The experimental result of scheme 2 is seen Fig. 9,10.Fig. 9 is a multi-target non-linear anti-interference excitation control oscillogram as a result, and Figure 10 controls oscillogram as a result for the PID excitation.Comparison diagram 9 and Figure 10 can see that also multi-target non-linear anti-interference exciting control method is calmed down the ability of vibration under the situation of big disturbance, be far superior to the PID excitation control method equally.Under the effect of multi-target non-linear anti-interference excitation control law, the unit vibration that short trouble causes was just calmed down on the right side through 3 seconds, and under the effect of PID excitation control law, the fluctuation of short circuit excision each running status after 6 seconds is not calmed down yet.

Conclusion: multi-target non-linear anti-interference exciting control method can improve the stable operation ability of electric power system greatly, and in that generator is meritorious when changing, still can accurately keep generator voltage and move on set-point.

Claims (6)

1, a kind of generator multi-target non-linear anti-interference exciting control method is characterized in that at first gathering phase voltage u from generator _a, u _b, u _cWith phase current i _a, i _b, i _cSignal is sent into A/D converter and is sampled, and after sampling is finished, these data is read the phase voltage real part U that calculates generator among the CPU by 16 Fu Shi sampling algorithms from the buffer of A/D _GaR, U _GbR, U _GcRWith imaginary part U _GaI, U _GbI, U _GcIAmplitude, and phase current real part I _GaR, I _GbR, I _GcRWith imaginary part I _GaI, I _GbI, I _GcIAmplitude after the sampled data of all passages calculated, further calculates Q again _G, U _G, U _Gd, U _Gq, Δ U _G, Δ ω, And δ, calculate multi-target non-linear anti-interference excitation control law then, further calculate the pilot angle α of controllable silicon in the three-phase fully-controlled rectifier, determine sending the time of SCR trigger pulse signal at last again according to excitation control law result of calculation UE, provide the timing value Na of timing microprocessor device, promptly finish one-period the Nonlinear Dynamic excitation Control work of generator.

2, by the described generator multi-target non-linear anti-interference exciting control method of claim 1, it is characterized in that the formula of multi-target non-linear anti-interference excitation control law is: $U_E=(\frac{K_1{Q}_G}{U_G}+U_G)+(K_2\sin \mathrm{\&delta;}-K_3\frac{U_{\mathrm{Gd}}}{U_{\mathrm{Gq}}}\cos \mathrm{\&delta;})\mathrm{\&Delta;\&omega;}+K_4\frac{U_G}{U_{\mathrm{Gq}}}(-k_1\mathrm{\&Delta;}{U}_G-k_2\mathrm{\&Delta;\&omega;}-k_3\mathrm{\&Delta;}\stackrel{\&CenterDot;}{\mathrm{\&omega;}})$

K in the formula ₁, K ₂, K ₃, K ₄, k ₁, k ₂, k ₃Be constant, can be in the real number scope value, common span is: K ₁=1.2～2.2, K ₂=0.56～33.25, K ₃=1.1～40.89, K ₄=2.06～42.75, k ₁, k ₂, k ₃Determine by the linear optimal computational methods.

3, a kind of generator multi-target non-linear anti-interference excitation controlling device, it is characterized in that forming by data acquisition circuit, microcontroller circuit and control impuls output circuit, difference is to adopt high performance eight passages, four road synchronized sampling A/D converter U20 in data acquisition circuit, CPU adopts high performance digital signal processor (DSP) U1 and tape program memory in the microcontroller circuit, and the memory under program storage has the programming of multi-target non-linear anti-interference excitation control law.

4, by the described generator multi-target non-linear of claim 3 anti-interference excitation controlling device, it is characterized in that data acquisition circuit comprises filter circuit and A/D converter, filter circuit by R45-R60, C1-C16, Z1-Z16 totally eight the cover form, be used for the generator voltage that filtering gathers, the humorous wave of high order and the high frequency random disturbances signal of current signal, A/D converter is made of U20 (MAX125) and C25-C29, C38, C39, R109 and A/D converter crystal oscillator X2.

5, by claim 3 or 4 described generator multi-target non-linear anti-interference excitation controlling devices, it is characterized in that microcontroller circuit includes digital signal processor (DSP) U1, electrification reset chip U2, E ²PORM memory U3, data memory U4, and crystal oscillator X1, pull out bit switch S1 at exclusion RP1, and U1 inside has the Flash type memory under program of 16K * 16bit,

6, by claim 3 or 4 described generator multi-target non-linear anti-interference excitation controlling devices, it is characterized in that the control impuls output circuit comprises: triode N1-N6, pulse transformer T1-T6, diode DM1-DM8, light-emitting diode L1-L6, resistance R M3-RM14, capacitor C 31-C36, form six road pulse signal amplification circuits, be respectively applied for six controllable silicons that trigger in an orderly manner in the three phase controlled rectifier circuit.

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